Method for determining the content of at least one given gas in a drilling mud, associated device and rig

Device for determining the content of at least one given gas in a drilling mud, of the type comprising calibration means comprising first means for the extraction, under predetermined conditions, of the gas contained in a calibration sample of a calibration mud;

• first means for measuring an item of data representing the quantity of at least one given gas in the gases extracted from the calibration sample, in at least two stages for extraction, under the predetermined conditions, in the first extraction means;
• means for establishing a family of curves representing the extraction, under the predetermined conditions, of the given gas contained in the drilling mud, on the basis of the measurements carried out by the first measuring means;
• analysis means comprising second means for the extraction, under the predetermined conditions, of the gas contained in an analysis sample of the drilling mud;
• second means for measuring an item of data representing the quantity of given gas in the gases extracted from the analysis sample, in a stage for extraction, under the predetermined conditions, in the second extraction means;
• and means for computing the given gas content of the drilling mud, on the basis of the quantity of given gas measured by the second measuring means and of a curve of said family.